Die casting machine



1941- R. J. SCHULTZ DIE CASTING MACHINE 2 Shets-Sheet l Filed July 16, 1941 ISnDentOr mug mend} Sc mfl Q5,

Clttorncgs Nov. 11, 1941. R. J. SCHULTZ DIE CASTING MACHINE Filed July 16, 1941 2 Sheets-Sheet 2 ISnnentor 2k Sa /1,1217% (It-tornegs .wmb

Patented 11, 1941 om CASTING MACHINE Raymond J. Schultz, Madison, Wis., assignor to Madison-Kipp Corporation, Madison, Wls., a

corporation of Wisconsin Application July 16, 1941, Serial No. 402,656

Claims.

This invention relates to die casting machines and particularly to machines of the type in which a ported pressure chamber is submerged in the melting pot in a substantially fixed position, the molten metal entering the'chamber through the ports and being displaced therefrom into the die by a plunger which closes the ports at the start of its displacement stroke.

In past constructions, the nozzle or discharge end of the pressure chamber has been fixed and the other end, at opposite sides of the plunger chamber, has been supported by laterally extending wings which "rest on the margins of the melting pot and are capable of limited sliding motion horizontally, but cannot move vertically. This construction results inoccasional fracture of the pressure chamber occurring either when the machine isshut down and as the metal in the pot-solidifies, or when solidified metal in the pot is being heatedup to melting temperature preparatory to putting the machine into action.

The present invention modifies the construction just described, in such a manner that the wing supports permit limited yielding both up and down against spring resistance of such character and range as to relieve the destructive stresses caused by thermal expansion and contraction, without impairing the alinement of the plunger, or its functional movements. Horizontal stresses are relieved by motion at the nozzle end.

The design of the spring support is such as to give the desired high spring resistance and still withstand the high operating temperatures.

A practical adaptation of the invention to a commercial die casting machine is illustrated in the accompanying drawingaln which:

Fig.- 1 is a side elevation'of so much of a die casting machine as is necessary to illustrate the invention.

Fig- 2 is a plan view Fig. 1. i

Fig. 3 is an end elevation, looking to the left relatively to Fig. 1. Fig. 4 is a view partly in vertical section and partly in elevation showing how the nozzle end of the pressure chamber is supported and confined.

Fig. 5 is an elevation of the parts shown in Fig. 4, looking to the right relatively to that figure.

Fig. 6 is a view partly in elevation and partly in section showing the yielding mounting for one of the two wings.

The pedestal ll supports the die mechanism part of which is illustrated. The only parts havof the parts shown.in

as to fill the same.

ing any direct relation to the present invention are the die components, generally indicated at 12 and the floating nipple plate l3 carried by bracket l4. ceives the nipple on the pressure chamber and connects it with the sprue inthe die, so that metal displaced from the pressure chamber is dlrected into the die.

and carries at its upperend the furnace chamber or mulile 16 in which the melting pot is received. The top of chamber Hi is closed'except for a main aperture of ovoid configuration, which is filled by the melting pot I1, and except for the two ofitakes If, H which include tubular extensions, as shown The melting pot conforms in plan to the contour of the opening in the top of chamber l6, so The form of the pot, as viewed in elevation is indicated in dotted lines in Figs. 1 and 3. Thus the pot depends into the furnace chamber I6 from a supporting marginal flange 2 I. This surrounds the pot, except at the end adjacent pedestal l I, and rests on a seat surrounlding the pot-opening in the top of chamber B.

Resting on flange 2| is the base flange 22 01a domed cover casting 23 which overlies somewhat more than half of pot IT. This has lugs 24 to support any suitable mechanism (not shown) used to operate the plunger. This mechanism may be hand or power operated and is not directly involved in the present invention.

The portions 25 of flange 22 (see Figs. 1 and 3) are each thickened and provided with an upstanding boss 26, beneath which the lower face is provided with a rectangular notch 21. The notches 21 are above opposite margins of potll and are alined with each other, and approximately aliried with the plunger chamber 28 of metal forcing unit 29. I

The metal forcing unit 29 comprises a hollow casting havingan inclined neck 30 with stiffening web 3|, the neck extending (as viewed in Fig. 1) upward and to the left from the bottom of the upright plunger chamber 28 and terminating in a nipple 32 which coacts with plate l3.. The plunger chamber is bushed, as indicated at 33, and a dischargepassage leads from the bottom of this chamber through the inclined neck 30 to the port in nipple 32.

Wing brackets 34 extend from opposite sides of the unit 29. They are alined and approximately centered on chamber 28, and terminate in pads 35 which enter and are free in the notches 21.

The nipple plate has a socket which re- The brackets 34 are each stiffened by top webs 35 and by two spaced flaring bottom webs'3l' which shroud the inlet ports 38 (see Fig. 6) through which molten metal enters the plunger chamber. The level of molten metal in pot I1 is kept near the top of the pot so that the ports 38 are submerged.

The bottom of plunger 39 rises on its up-stroke far enough to clear ports 38, and on its downstroke first closes the ports and then displaces metal from the chamber 28 through the nipple 32 as is usual in machines of this type.

As stated the pads 35 are free in notches 21, but the range of motion is not sufficient to impair the alinement of the plunger. shouldered studs II are threaded into the tops of pads 35 and are closely guided in vertical ways drilled through the bosses 26. Fixed to the upper end of studs ll are heavy spring elements 42 whose form is clearly shown in the drawings, see particularly Figs. 3 and 6.

These spring elements comprise a central hub 43 in which the upper end of stud M is fixed by a nut and f o looped spring ends which seat on portions 25 if flange 22 and are fixedly held thereto by nuts on the studs 44. The studs 44 pass through the ends of the springs 42, the thickened portion 25 of flange 22 and through flange 2!. They are threaded into the top of housing l6. Machine screws 65 further connect flanges 22 and 2! to the top of chamber Hi.

In this way a rigid support is provided for the plunger actuating mechanism, but the chambered end of the metal forcing unit 29 is permitted very limited vertical motion up and down from its normal reutral position against heavy resistance offered by the springs 42. Additional fictional resistance may be imposed by setting up the thrust screws 46. These are provided with check nuts to preserve their adjustment.

The neck portion of the unit 29 is sustained immediately behind nozzle 32 in an orifice formed partly in the pot i! and partly in the dome 23 (see Figs. 4 and 5). The nozzle has an arcuate boss or rib 41 which seals with the pot H. A set screw 48 threaded in a boss formed in the dome 23 exerts the desired sealing pressure. The screw 48 is locked by a check nut.

The construction is such that the plunger and plunger chamber are held in alinement, but limited vertical motion of the chamber is permitted adjacent the plunger. However. the springs are so stiff that they do not yield appreciably to the stresses imposed by the plunger. Horizontal creep is permitted adjacent the nipple. Thus shrink strains are relieved and fracture of the unit thereby is avoided, during both heating and cooling of the melting pot,

While some details of the die casting machine have been described to indicate the environment in which the invention develops its utility, the form of the machine is obviously subject to Wide variation. The details of mounting the pressure unit in any appropriate die casting machine are the real subject of invention and they too are subject to modification within the scope of the claims which alone define the scope of the invention.

What is claimed is:

l. The combination of a plunger; a pressure unit adapted to be submerged in molten metal and comprising a transverse pressure chamber adapted to receive said plunger and a longitudinal nipple in communication with and remote from said chamber; and a three point support for said unit, comprising means embracing said nipple: and permitting longitudinal motion thereof as an incident to thermal expansion and contraction, two guides adjacent, and parallel with the axis of, said chamber and engaged by portions of said unit, and yielding means serving to center said units in said guides, the yielding means being of sufficient strength to resist the reaction of the plunger, and capable of yielding to relieve shrinkage strains.

2. The combination defined in claim 1 in which the yielding means comprise heavy arcuate spring loops, and the guides include limit stops which so limit motion of the unit as to prevent substantial misalinement of the plunger and pressure chamber.

3. In a die casting machine, the combination of a melting pot; a metal forcing unit at least partially submerged in molten metal in said pot, said unit having at one end a vertical plunger chamber and at the other end a horizontally extending nipple communicating with said chamber; clamping means embracing said nipple and adapted to permit limited horizontal motion; vertical guides for said unit adjacent said chamber and on opposite sides thereof; and yielding means associated with said guides and adequate to sustain said unit against the stresses occasioned by normal operation of the machine, but serving to relieve shrinkage strains.

4. In a die casting machine, the combination of a melting pot; a metal forcing unit at least partially submerged in molten metal in said pot, said unit having at one end a vertical plunger chamber and at the other end a horizontally extending nipple communicating with said chamber; clamping means embracing said nipple and adapted to permit limited horizontal motion; vertical guides for said unit adjacent said chamber.

and on opposite sides thereof; yielding means associated with said guides and adequate to sustain said unit against the stresses occasioned by normal operation of the machine, but serving to relieve shrinkage strains; and limit stops associated with said guides.

5. In a die casting machine, the combination of a melting pot; a metal forcing unit at least partially submerged in molten metal in said pot, said unit having at one end a transverse plunger chamber and at the other a nipple communicating with said chamber and extending substantially at right angles to the axis thereof; supporting means adjacent said chamber for guiding said unit in limited motion in a direction parallel with the axis of said chamber; yielding sustaining means associated with said guiding means; and means for clamping said nipple while permitting limited motion in the direction of the axis thereof.

RAYMOND J. SCHULTZ. 

